1. Field of the Invention
The present invention generally relates to improvements in the structure and function of a musical instrument, more particularly, the present invention relates to improvements in the structure and function of a reeded instrument, such as a harmonica.
2. Background Information
Reeded instruments, such as for example, without limitation, the saxophone, oboe, reed organ, Chinese sheng, and harmonica produce musical notes or tones generally by way of a vibrating reed. Harmonicas produce musical tones by a player blowing air into, or drawing air from, a mouthpiece in a manner that causes one or more of the reeds therein to vibrate. One popular form of the harmonica is the ten-hole diatonic harmonica, having two reeds per hole, although there are numerous variations having different numbers of holes, and reeds per hole.
As shown for example in FIG. 1, the typical construction of a diatonic harmonica includes a pair of reed plates attached to opposing faces of a comb providing ten cells. Each plate contains a set of ten flexible metallic reeds each affixed above rectangular slots through which the reeds vibrate. The reeds of each cell are configured such that one is preferably played when blowing and the other when drawing (See, FIG. 2). The Richter-tuned harmonica, the most widely known type of harmonica, is tuned such that the blow notes comprise the tonic triad (e.g. C-E-G for a harmonica tuned to the key of C) and the draw notes provide the dominant (G major) chord. Because the standard diatonic harmonica is only designed to be played in a single key at a time, diatonic harmonicas are available in all keys.
The pitch or frequency of vibration of a given reed is governed by several factors, including the reeds mass and stiffness. In general, the frequency of a given reed is proportional to the square root of the ratio of the reeds stiffness to mass.frequency∝√{square root over (stiffness/mass)}
It is in fact common practice to tune a reed to a desired pitch by removing material from the tip, thereby reducing the mass of the reed and raising its pitch; or by removing material from the root, thereby reducing the stiffness of the reed and thus lowering its pitch.
The pitch is also related to a lesser extent by the acoustic admittance of the player's vocal tract. By modifying the vocal tract, it is possible to flatten (lower the pitch) of the greater pitched reed in a given cell. A moderately advanced diatonic harmonica player can thereby produce twelve additional tones by a process known as “bending,” whereby the player modifies the resonant volume in the vocal passage, principally with the tongue, to “bend” or adjust the tone produced to achieve the desired pitch. A “bend” is therefore a procedure involving the adjustment of the player's embouchure, wherein a tone is flatted by causing the normally idle lower-pitched reed of the reed pair in a harmonica to vibrate in its opening mode.
A more advanced player can also produce four additional tones by a technique known as “overblowing,” whereby the player more strictly matches the appropriate resonant volume with the tone he or she wishes to produce, typically causing the draw reed of the first, fourth, fifth, and sixth holes to produce tones corresponding to a flatted third of the low octave and a flatted third, fifth, and seventh respectively of the middle octave. Similarly, drawing and a strictly controlled shaping of the resonant passage will produce “overdraw” tones from the blow reeds corresponding to a sharped first, fifth and eighth of the highest octave. Therefore, an overblow or overdraw procedure is one in which the tone is sharped by causing the higher pitched reed in a harmonica reed pair to vibrate in its opening mode. Overblow occurs on the first six holes of a standard diatonic harmonica wherein the higher-pitched reed is the draw reed; overdraw occurs on the last four holes of a standard diatonic harmonica wherein the higher-pitched reed is the blow reed.
A problem associated with conventional harmonica play is that the player must modify his or her oral cavity to achieve certain bends, overblows, or overdraws. Low draw bends typically require excessively large embouchure, necessitating that the jaw be lowered and the tongue positioned low in the oral cavity. Conversely, overblows, blow bends, and overdraws require relatively small oral volume and that the tongue of the musician be positioned against the palate with the tip forward against the upper teeth.
In all, using the normal playing, bending, overblowing, and overdrawing techniques, the most skilled diatonic harmonica player can produce a total of thirty-eight tones from the ten-hole diatonic harmonica. The technique of overblowing is extremely difficult and diatonic harmonica players, even those of great skill, have been known to practice the technique for years before feeling comfortable enough to use the technique in a live performance. The same can be said of the “overdrawing” technique.
Furthermore, both overblow and overdraw on a diatonic harmonica causes a sudden jump in pitch, unlike the bent notes which permits a gradual transition between notes. Such sudden jump limits the expressiveness of the player.
Because the seven tones achieved by overblowing or overdrawing are not readily achieved on a ten-hole diatonic harmonica, many players resort to a chromatic harmonica, which offers a full chromatic scale of semitones by means of a slide that directs air to separate sets of reeds, each of the separate reeds being pitched a semitone higher than those activated without the slide. However, the transition between reeds on a chromatic harmonica is discrete—analogous to the keys of the piano. It is not possible to gradually alter the pitch, as would be possible for example on a slide trombone, guitar, violin, and other instruments. It is therefore impossible to induce a desirable tremolo effect, as would be possible on such aforementioned instruments.
Furthermore, the pitch produced by both the diatonic and chromatic harmonicas is relatively insensitive to the loudness of sound produced. There are however circumstances in which the modulation of pitch with loudness is desirable.
A number of devices have been used to improve the playing of harmonicas. For example, U.S. Pat. No. 574,625, discloses a siding mouthpiece for transferring a blast of air from one cell chamber to another without moving the lips. U.S. Pat. No. 1,671,309, discloses a chromatic harmonica having a frontal slide which occludes certain blow holes in the harmonica to allow the player to achieve a chromatic scale, as opposed to a diatonic scale. Other chromatic harmonicas having blow hole-occluding devices include U.S. Pat. Nos. 1,752,988; 2,005,443; 2,339,790 and 2,675,727.
U.S. Pat. No. 5,739,446 to Bahnson, discloses a harmonica and method of playing which involves the use of a valve mechanism. A sliding set of louvers is added to one side of each reed plate, which apparently, when activated, block the air leakage from the inactive reed. This mechanism appears to be relatively complicated and expensive to implement. The Bahnson harmonica also appears to require the player to activate the valve at the exact instant that the overblow note is to be played, thus requiring additional motions and interaction with the harmonica by the player, and preventing modulation of frequency as required for certain tremolo effects.
U.S. Pat. Nos. 5,182,413 & 5,367,937 to Epping discloses a harmonica that also provides gradual transition of pitch, but through the use of additional sets of reeds. To increase the musical range of the instrument, the Epping harmonica has four reeds per reed cell. Two “enabler reeds” are provided in addition to the traditional blow and draw reeds for enabling the blow and draw reeds to both be bent to lower frequencies. All four reeds have check valves which are essential for the enabler reeds to preclude unwanted sympathetic vibration in adjacent cells. This mechanism also appears to be relatively complicated and expensive to implement.
Accordingly, an advance in the art could be realized if a harmonica could be constructed which readily permits the modulation of pitch, enabling players with limited skills to achieve bent notes, and enable both advanced and novice players the ability to smoothly modulate the pitch of any one note, or combination of notes. Another significant benefit could be realized from a harmonica that is more susceptible to the techniques of bending, overblowing and/or overdrawing.